Three-dimensional ultrasound assessment of endometrial receptivity: a review

Abstract

Three-dimensional ultrasound (3D US) is a new imaging modality, which is being introduced into clinical practice. Although this technique will not probably replace two-dimensional ultrasound, it is being increasingly used. It has been reported that 3D US is a very high reproducible technique. The endometrium has been paid special attention when using this technique. The aim of this paper is to address some technical aspects of 3D US and to review critically its current status in evaluating endometrial function with special focus in its role in predicting pregnancy in assisted reproductive techniques. In spontaneous cycles endometrial volume grows during follicular phase remaining constant through the luteal phase. Endometrial vascularization increases during follicular phase peaking 2-3 days before ovulation, decreasing thereafter and increasing again during mid and late luteal phase. Data from studies analysing the role of 3D US for predicting IVF outcome are controversial. An explanation for these controversial findings might be different design of reported studies, specially the timing of ultrasound evaluation.

Figure 1

Three-dimensional ultrasound depicting multiplanar display of the uterus. All three orthogonal planes can be displayed using this technique.

Figure 2

Endometrial volume calculation by using the VOCAL software after three-dimensional ultrasound.

Figure 3

3D-Power Doppler indexes for assessing endometrial vascularization by means of the three-dimensional ultrasound.

Figure 4

Determination of the subendometrial area volume by using the "shell" facility. In this case 5 mm has been chosen.

Figure 5

Vascularization of the subendometrial area by 3D-Power Doppler. VI, FI and VFI refers to the shell area, not the endometrium.